Yield, water use and yield response factor of flue-cured tobacco under different levels of water supply at various growth stages

2009 ◽  
Vol 59 (4) ◽  
pp. 453-464 ◽  
Author(s):  
Recep Çakir ◽  
Ulviye Çebi
2016 ◽  
Vol 46 (7) ◽  
pp. 1145-1150 ◽  
Author(s):  
Daniel Fonseca de Carvalho ◽  
Dionizio Honório de Oliveira Neto ◽  
Luiz Fernando Felix ◽  
José Guilherme Marinho Guerra ◽  
Conan Ayade Salvador

ABSTRACT: The aim of the present study was to evaluate the effect of different irrigation depths on the yield, water use efficiency (WUE), and yield response factor (Ky) of carrot (cv. 'Brasília') in the edaphoclimatic conditions of Baixada Fluminense, RJ, Brazil. Field trials were conducted in a Red-Yellow Argisol in the 2010-2011period. A randomized block design was used, with 5 treatments (depths) and 4 replicates. Depths were applied by drippers with different flow rates, and the irrigation was managed by time domain reflectometry (TDR) technique. The reference (ETo) and crop (ETc) evapotranspiration depths reached 286.3 and 264.1mm in 2010, and 336.0 and 329.9mm in 2011, respectively. The root yield varied from 30.4 to 68.9t ha-1 as a response to treatments without irrigation and 100% replacement of the soil water depth, respectively. Values for WUE in the carrot crop varied from 15 to 31kg m-3 and the mean Ky value was 0.82. The mean values for Kc were obtained in the initial (0.76), intermediate (1.02), and final (0.96) stages. Carrot crop was influenced by different water depths (treatments) applied, and the highest value for WUE was obtained for 63.4% of soil water replacement.


Author(s):  
Safiye Pınar Tunalı ◽  
Talih Gürbüz ◽  
Necdet Dağdelen ◽  
Selin Muradiye Akçay

This study was conducted in the Aegean region conditions of Turkey in 2020. It was carried out on May-505, a local cotton variety. The study examined the variation of seed yield, water use efficiency (WUE), and irrigation water use efficiency (IWUE) of cotton with different irrigation programs and water levels. The field trial, which was designed as two factors and three replications, was designed according to the randomized complete block trial design. Four different irrigation levels (IL) (100%, 67%, 33%, and 0%) and two different irrigation scheduling approaches (gravimetric and pan evaporation) were investigated in the study. Seasonal water use values in treatments varied between 215 (0%) and 746 (100% - Pan evaporation approach) mm during the production period. The average yield values obtained with irrigation levels, which have essential effects on cotton seed yield, are listed as follows; 2057 kg ha-1 (IL-0%), 3471 kg ha-1 (IL-33%), 3771 kg ha-1 (IL-67%), and 5083 kg ha-1 (IL-100%). It was determined pan evaporation applications performed higher yields than gravimetric applications. WUE values were between 0.63 – 1.04 kg m-3. The gravimetric method’s yield response factor (ky) was 0.73, and the pan evaporation method’s yield response factor (ky) was 0.89. These results show that cotton is tolerant of water stress. In conclusion, although the pan evaporation approach with 100% treatment is suggested for cotton production in the parts of the Aegean region within the semi-arid climate zone, while water resources are sufficient. When the results are evaluated in terms of seed cotton yield for a deficit irrigation strategy, IL-67% treatment with a gravimetric approach can be used.


2018 ◽  
Vol 67 (2) ◽  
pp. 149-156
Author(s):  
Borivoj Pejić ◽  
Ksenija Mačkić ◽  
Predrag Randjelović ◽  
Ivan Valtner ◽  
Jelica Gvozdanović-Varga ◽  
...  

Summary The objective of this study, conducted in the northern Serbian province of Vojvodina, was to analyze the effect of surface and subsurface drip irrigation (with drip lateral placement depths of 0.05 and 0.1 m) on the yield and water productivity of onions (Allium cepa L., var. ‘Holandski žuti’). The irrigation applied was scheduled on the basis of the water balance method. The daily evapotranspiration rate was computed using the reference evapotranspiration (ETo) based on the Hargreaves equation and the crop coefficient (kc). The irrigation rate was 30 mm, whereas the amount of water added by irrigation during the season was 150 mm. According to the results obtained, the onion yield under irrigated conditions was significantly higher than that under non-irrigated (control) conditions. Differences in the yield obtained using surface and subsurface irrigation were non-significant. The amounts of water used for evapotranspiration under irrigated and non-irrigated conditions were 363 mm and 220 mm, respectively. The value of the surface irrigation yield response factor (Ky) was 0.62, whereas the values of the subsurface irrigation yield response factor (Ky) were 0.61 (0.05 m) and 0.79 (0.1 m). Consequently, onions grown from sets proved moderately sensitive to water stress under regional climate conditions and could be grown without irrigation. The value of the irrigation water use efficiency (Iwue) ranged from 3.55 to 4.97 kg m−3, whereas the value of the evapotranspiration water use efficiency (ETwue) ranged from 3.72 to 5.22 kg m−3. The highest yield of onions was obtained using a drip lateral placement depth of 0.1 m, which is recommended for high-yielding onion production.


Agric ◽  
2019 ◽  
Vol 30 (2) ◽  
pp. 111-116
Author(s):  
Farhan Ahmad Abdulrahman ◽  
Hawrez Ali Nadir

This study was conducted in Technical College of Applied Sciences, Sulaimany Polytechnic University, during 2017. Different levels of irrigation were used to production of okra plant. Complete Randomize Design used to layout of the experiment, with three level of irrigation in four replications. Yield, fresh weight of plant, dry weight of plant, yield response factor and different levels of irrigation were observed. The highest yield was given from treatment T1 (3.17 t/ha.) and the lowest was given from T3 (2.988 t/ha.). Also, the maximum fresh weight and dry weight of plant were given from T1 (61.40, 11.218 t/ha.), and their minimum was given from treatment T3 (57.00, 8.783 t/ha.). The highest water use efficiency and harvest index were obtained from T3 (1.615 kg.m-3, 0.095), and the lowest was given from treatment T1 (1.055 kg.m-3, 0.094). The crop response factor and the results in this study showed that the okra plants have a good response of water stress.  As a result, we can recommend cultivating the okra at that time without irrigation in that region. 


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1224
Author(s):  
Yanzhe Hu ◽  
Shaozhong Kang ◽  
Risheng Ding ◽  
Taisheng Du ◽  
Ling Tong ◽  
...  

The accurate quantification of crop water use or evapotranspiration (ET) under water and salt stress is needed for efficient water management and precision irrigation in water scarce regions. However, few studies were examined on alfalfa water use and its components under water and salt stress. We carried out two field experiments to quantify alfalfa water use through setting up different water and salt gradients, including two irrigation levels (full and deficit irrigation) and four soil salinity levels (0, 2‰, 4‰ and 6‰ salt of mass ratio) in an arid region of Northwest China. Electrical conductivity of soil saturation extract (ECe), soil water content (SWC), leaf area index (LAI) and soil evaporation (E) were measured. The SIMDualKc model, which uses the FAO56 dual Kc approach, was calibrated and validated using measured SWC and E. Model results show a good agreement between observed and simulated SWC and E without stress. The depletion fraction for no stress (p) and the percent yield reduction per unit increase in soil salinity (b) were 0.50 and 6.0%/(dS m−1), respectively, slightly lower than those of FAO-56 (0.55 and 7.3%/(dS m−1)). The difference indicates that alfalfa has a lower capacity of water use but a greater tolerance to salt stress after soil salinity reached its sensitivity threshold in the arid region. The model performed a reduced accuracy under water and salt stress and the differences tended to increase as stress increased, which was partly attributed to constant yield response factor (Ky) under different soil water and salt stress. The key parameter Ky dynamically increased with the increased degree of stress. Compared to constant Ky, the simulations of SWC and E showed improved accuracy with dynamic Ky. These results suggested that the response and acclimation of alfalfa to stress might be incorporated into the dual Kc model through the diversity of Ky.


2016 ◽  
Vol 38 (4) ◽  
Author(s):  
BENITO MOREIRA DE AZEVEDO ◽  
GUILHERME VIEIRA DO BOMFIM ◽  
JOAQUIM RAIMUNDO DO NASCIMENTO NETO ◽  
THALES VINÍCIUS DE ARAÚJO VIANA ◽  
DENISE VIEIRA VASCONCELOS

ABSTRACT Local knowledge about irrigation management in yellow melon can promote higher precision to water supply for irrigation purposes, increasing productivity and reducing production costs. The aim of this study was to evaluate the effects of different irrigation depths for yellow melon production and on yield response factor to water (Ky) in the productive phase. The experiment was carried out in Fortaleza, state of Ceará, Brazil, in complete randomized blocks with six treatments, four replicates and six plants per plot. Treatments were applied from intermediate (III) to final (IV) physiological state with water depths equivalents to 25%, 50%, 75%, 100%, 125% and 150% of the crop evapotranspiration (ETc). Ky was calculated according to FAO-33 report methodology in the range from 25% to 100% ETc. The variables analyzed were number of fruits per plant, polar and equatorial diameters, fruit fresh weight, commercial yield, skin and pulp thickness, and soluble solids. Treatments influenced the number of fruits per plant, equatorial diameter, fruit fresh weight, commercial yield, and soluble solids. The best results were reached with commercial yield equal to 32.2 Mg ha-1, 1.46 fruits per plant, equatorial diameter equal to 16.3 cm, fruit fresh weight equal to 2.3 kg and soluble solids equal to 12 ºBrix with 100.3% ETc in the productive phase. The crop was tolerant to water supply reduction on the productive phase (Ky < 1) through daily irrigation with controlled water deficit.


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